Process for the industrial separation of lead and zinc contained in the state of sulfids in ores.



G. DE BEcHl. PROCESS FOR THE INDUSTRIAL SEPARATION OF LEAD AND ZINC CONTAINED IN THE STATE 0F SULFIDS IN ORES. 1

APPLICATION FILED MAR. 29. I9I3'. n

Patented Oct. 19, 1915.

Mixed 1"E l UNITED sTATEs PATENT oEEIoE.

GUY DE BECHI, OELONDON, ENGLAND.`

PROCESS FOB THE INDUSTRIAL SEPARATION F LEAD .AND ZINC CONTAINED IN THE STATE 0F SULFIDS IN DRES.

Specification of Letters Patent.

Application filed Mar-ch 29, 1913. Serial No. 757,694.`

vented certain new and useful Improve,-y

ments in Processes for the Industrial Separation of Lead and Zinc Contained in the State of Sulds in Ores,of which the fol-v lowing is a specification. l

It is known that the industrial separation of blende and galena in ores in which these substances are intimately mixed is very diflicult and that the means for mechanical separation give only imperfect results.

This invention has for its object to eect the separation of the two metals' chemically by transforming their sulfids into sulfates.-

In the drawing, the entire process is illustrated diagrammatically.

In carrying out the process, the ore is -iirst reduced to impalpable powder and is treated in suitablev apparatus by a heated solution, at a suitable temperature, of ferrie sulfate Fe2(SO4)3 containing a suitable quantity of `duced to ferrous sulfate sulfuric acid and nitric acid, or nitrates.

Under the influence of ferrie sulfate the sulfids of lead and 0f zinc are transformed into sulfates, the ferric sulfatebeing re- FeSO,i according to the following equations:

The nitric oxid evolved is again oxidized in suitable apparatus thus regenerating the nitric acid, which serves for a fresh opera-I tion. The transformation of the nitric`oxd into nitric'acid by means of water and air is an operation which is well known and'takes place according to the equation:`

The Equid obtained Magnet of the ferric sulfate on the sulfids contained in the treated ore, contains, in a soluble state, zinc,

and in an insoluble state, lead sulfate as well as Simple filtration in suitable apland during the operations. p

tion.'

mation of free sulfur, se sulfate from the lead sul Patented oet. 19, 1915.'

paratus allows ofthe separation of the lead and zine. If the operation has been carried out with an already saturated solution of zinc sulfate, arising from a preceding operation, which is the case in practice, the zinc sulfateformed from the ore, crystallizes by cooling and can be separated by decanting,

hydro extracting or filtering or in any other suitable manner. The mother-liquors serve for treating afresh quantity of ore while, by calcining the zinc sulfate in suitable furnaces the sulfuric acid necessary for the re'- action is regenerated as above described. The residue from the calcination kof the zinc sulfate in the furnace Vis zinc oxid, free from lead, which is transformed into metallic zinc by known processes. t

As to the insolublepart which remains upon the filter when treating the ore by ferrie sulfate and which contains all the lead and sulfur, it is dried, and the sulfur is separated by distillation orl by extraction with a suitable solvent. The inal residue, which contains all the lead, and the precious metals, (should any be present) contained in the ore, is transformed in this case into argentiferousand auriferous lead by the usual metallurgical processes.

The-above described process does not req'uire other reagents thanV those obtained from the ore itself with the exception of those required to replace the slight loss of acids Ainherent to all industrial processes which may be replaced at small cost What I claim is:

1Q 'A processfor the industrial separation of lead and zinc contained 1in the state of sulphids in ores consisting in reducing the ore to an impalpable powder, treating said lpowder by a mixture of ferric sulfate, sulfurie acid and'nitric acid, whereby the suliids are transformed into sulfates with formation of free sulfur, l'and separating the z i'nc' solution from the lead sulfate by filtra- 2. A process for the industrial separation fof leadand zinefcontained'in the state of "suld'sin ores,""consisting in 'reducing the oretofan inp'alpable powder, treatingsaid powder by a mixture of ferrie sulfate, sulfuric acid and nitric acid, whereby the sul'- ds are transformed into sulfates with forarati-ng the' zinc ate by filtration,

and regenerating the sulfuric acid of the zinc sulfate.

3. A process for the industrial separation of lead and zinc contained in the state of sulids in ores, consisting in reducing the ore to an impalpable powder, treating said powder by a mixture of ferrie sulfate, sulfurie acid and nitric acid, whereby the sulids are transformed into sulfates with format-ion of free sulfur, separating the zinc sulfate from the lead sulfate by iltration, regenerating the sulfuric acid ofthe zinc sulfate, and extracting the sulfur from the insoluble residue.

4. rlFhe process of extracting lead and zinc from ores7 comprising reducing the ores to a line powder, and subjecting said powder to the action of a ferrie salt solution containing nitric acid, whereby said ferrie salt is maintained oxidized during the extraction of the ore.

ln testimony whereof I have afliXed my signature in presence of two witnesses.

GUY DE BECHI.

`Witnesses JAQUEs BEBE, CHAs. ROY NASMITH. 

